Abrasive tool



R. A. MOCRE ABRAS IVE TOOL v Nov. 16, 1943.

Filed Aug. 5. 1942 foga/8TH. MOORE @QM/MJ 14 h. www

Patented Nov.`16, 1943 UNITED s'rA'riazsv PATENT OFFICE;

ABRASIVE TOOL Robert A. Moore,-Dallas'1ex., assignor of onetwentieth to TedlC. Beshear, Corpus Christi,

Tex.

Application August 3, 1942, Serial No.,453,335

5 Claims. (Cl. 51-195) The invention relates to abrasive tools, es

pecially grinding disks, and-t9 an improved meth# od of manufacturing the same.

r One of the objects of theinvention is to pro- A'vide' a 'composite abrasive disk havinggrinding surfaces on both sides thereof. l

Another object is to provide an abrasive tool having one or more grinding surfaces each including intercommunicating openings, grooves, I channels, depressions andthe like, thereby providing air-ways for' cooling the tool and `passages through which waste material may pass, thus preventing clogging of the'grinding surface or surfaces. M i

A further object of the invention is to'yprovide a grinding tool having abrasive material so ar,`

Fig. 1 is a plan view of one surface of an abl rasive disk embodying the invention;

Fig. 2 is a similar view showing the opposite surface of the disk; 1 l Fig. 3 is a -diagrammatic view illustrating the tool in operation;

Fig. 4 is a section on the line 4 4 of Fig. 2, and Figs. 5 and 6 are views illustrating successive steps in the process of making the abrasive tool.

Referring in detail to the drawing; the reference numeral I0 denotes a base sheet which may be of cardboard, breboard, leatherboard or other suitable thin, relatively inexpensive and preferably somewhat flexible material. Each of the opposite surfaces of the disk is provided with spaced abrasive areas formed by causing particles of carborundum or other hard, gritty material to'adhere to such surfaces. As shown in Fig. l the abrasive areas II on one surfaceare .formed of particles of different size than the particles making up-the areas I'Ia on the opposite face, as shown in Fig.l 2. The central portions I2 and i2a on opposite surfaces of the disk remain uncoated, and upon these uncoated portions may be provided suitable indicia, as the name of the company, the trade-mark, and the size or grade o'f the particles making up the abrasive surface. Obviously, any suitable designation may be-provided on the uncoated surfaces. Radiating from the central uncoated portions -ll2 and Iza are a plurality of curved channels I3,.

I3a which extend from the central portion to the periphery of the disk. It will be noted that the V channels I3 and I3a are arranged in pairs each radiating from a" corresponding position on opposite faces vof the disk but curved in opposite directions. A plurality of openings i4, .I4 corresponding Vin number to the pairs of. channels are provided, each being located substantially at the point Where the pairs of channels radiate from the central depressed portions I2 and IZa Thus the channels on opposite faces are intercom' nected and the radial channels allcommunicate with the central depressed portion, thereby forming a. series of communicating channels and air-ways.l for cooling the disk and insuring cleaning of the disk of, dust, debris and the like during operation of the tool.

In addition to providing channels for cooling and cleaning purposes, the curved channels I3 and I3a are soshaped as to provide sharp points or cutting edges |5, I5af at the extremities of the abrasive coated areas II and Ila. Thus when the disk is rotated in the direction of the arrow as indicated in either Fig. l or Fig. 2 there is insured a shear cut which has been found very effective in abrading operations.

At the center of the disk there is provided an opening I6 to permit attachment to a rotatable shaft I'I by means of suitable fastening means I8. The fastening means are preferably coun'- tersunk so as to prevent contact of lsuch fastening means with the surface to be abraded when the disk is placed iiat upon the said surface.

In operation the abrading tool may be applied to the surface either inclined, as indicated in Fig. 3, or flatwise. A very effective result is obtained where the tool is applied in the inclined position,

owing to the flexibility of the base material to 'which the abrasive particles are applied. Owing to this flexibility curvature of th disk results when one edge is pressed on the surface to be abraded and this insures a firm but yielding applicationo the abrasive materials. 'Ihe disk is self-cleaning and self-cooling owingto the presence of the intercommunicating channels and Openings. it being observed that each chann'elI has an inlet and an outlet so that no clogging either of dirt or air results. Even when the disk is applied flatwise to a surface to be abraded the intercommunicating channels are still eifective and both air and waste material are 4enabled to pass freely through the openings Il to the lopposite side ofthe disk. The waste material will of course be thrown out by centrifugal force assisted -by air currents. If desired other openings passing' through the disk may be located within the channels I3, 13a and in the central uncoated portion or channel l2.

The disks may be cheaply and efliciently manufactured. Steps in the manufacture are illusv These spaced areas correspond with the abrasive areas on the finished disk. When the adhesive has been applied abrasive particles may then be sprinkled upon the disk and will adhere onl.l to the areas upon which the adhesive is located, the

uncoated portions which correspond with the central depression i2 and radiating channels I3 will not retain the particles, which fall olf or may be brushed off after the adhesive has dried. This method of coating is vary rapid since the adhesive may be applied to a large number of disks and the abrasive applied to all the disks by a blowingr operation. y y

' It will be obvious that various types of patterns may be employed i'n producing the improved abrasive tool. It vrnay be desirable to form a number of patterns upon a single sheet before cutting the sheet into individual elements. Where such pattern is employed the glued areas for a number of tools may all be coated with abrasive materialin spaced areas before the final individual unit is stamped or cut from the composite sheet. After one surface'` of'tbe tool has been coated J with abrasive material and the adhesive suitably dried theother surface may be coated in a sim- ,e

the purpose of illustration, but it will be' obvious that numerous modifications and variations may be resorted to without departing from the spirit of the invention.

I claim:

1. An abrasive disk adapted for use as a rotary tool, comprising a base sheethaving a working face comprising a smooth circular central area.

' and an outer portion comprising a plurality of spaced abrasive areas formed of abrasive particles adhesively secured to the base sheet, each abrasive area extending continuously from the central area to the periphery of the disk, said abrasive areas being separated by curved radial channels extending from the central area to the periphery, the channels being bounded by curves intersecting the periphery of the disk at an acute angle, considered in the direction of rotation of the tool, whereby the `abrasive areas are provided with sharp cutting edges. and whereby air is forced through the channels by rotation of the disk to cool the tool during operation.

2. An abrasive disk as set forth in claim 1, in which the base sheet is similarly coated on opposite sides thereof, to provide optionally usable working faces, there being central uncoated areas on each face, and the curved lchannels extending from each central area to the periphery, the channels on opposite faces being oppositely curved.

. 3. An abrasive disk as set forth in claim l, wherein openings extending through the disk are provided at the juncture of each channel with the central area.

4. An abrasive disk as set forth in claim 1, having similarly coated areas on pposite faces separated by curved channels, the channels on opposite faces radiating from corresponding positions but being oppositely curved.-

5. An abrasive disk as set forth in claim 1, having similarly coated areas on opposite faces separated by curved channels, the channels on opposite faces radiating from corresponding portions but being oppositely curved, and openings extending through the disk at the juncture of each channel with its central area, each opening communicating with a pair of channels, one on each face of the disk.

ROBERT A. MOORE. 

